Not lifting finger: knuckle not working? (4-4)

I believe the answer is:

bone-idle

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'not lifting finger knuckle not working?' is the definition.
I can't judge whether this definition defines the answer.

'lifting finger knuckle not working?' is the wordplay.
'lifting' is a charade indicator (letters next to each other).
'finger knuckle' becomes 'bone' (I can't explain this - if you can you should give a lot more credence to this answer).
'not working?' becomes 'idle' (idle means doing no work).
'bone' put next to 'idle' is 'BONE-IDLE'.

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I've seen this clue in The Sun.

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